Designation D5109 − 12 Standard Test Methods for Copper Clad Thermosetting Laminates for Printed Wiring Boards1 This standard is issued under the fixed designation D5109; the number immediately follow[.]
Designation: D5109 − 12 Standard Test Methods for Copper-Clad Thermosetting Laminates for Printed Wiring Boards1 This standard is issued under the fixed designation D5109; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision A number in parentheses indicates the year of last reapproval A superscript epsilon (´) indicates an editorial change since the last revision or reapproval Referenced Documents Scope* 2.1 ASTM Standards:2 D150 Test Methods for AC Loss Characteristics and Permittivity (Dielectric Constant) of Solid Electrical Insulation D229 Test Methods for Rigid Sheet and Plate Materials Used for Electrical Insulation D257 Test Methods for DC Resistance or Conductance of Insulating Materials D374 Test Methods for Thickness of Solid Electrical Insulation (Withdrawn 2013)3 D618 Practice for Conditioning Plastics for Testing D1531 Test Methods for Relative Permittivity (Dielectric Constant) and Dissipation Factor by Fluid Displacement Procedures (Withdrawn 2012)3 D1711 Terminology Relating to Electrical Insulation D1825 Practice for Etching and Cleaning Copper-Clad Electrical Insulating Materials and Thermosetting Laminates for Electrical Testing (Withdrawn 2012)3 D1867 Specification for Copper-Clad Thermosetting Laminates for Printed Wiring D3636 Practice for Sampling and Judging Quality of Solid Electrical Insulating Materials E53 Test Method for Determination of Copper in Unalloyed Copper by Gravimetry 2.2 Other Standard: NEMA Publication Number LI 1-1975 Test for Hot Peel Strength of Copper-Clad Industrial Laminates for Printed Circuits4 1.1 These test methods cover the procedures for testing copper-clad laminates produced from fiber-reinforced, thermosetting polymeric materials intended for fabrication of printed wiring boards 1.2 The procedures appear in the following sections: Procedure Referenced Documents Conditioning Dielectric Breakdown Voltage Parallel to Laminations Dimensional Instability Dissipation Factor Flammability Rating Test Flexural Strength, Flatwise at Elevated Temperature Flexural Strength, Flatwise at Room Temperature Oven Blister Test Peel Strength Test at Elevated Temperature Peel Strength Test at Room Temperature Permittivity Pin Holes in Copper Surface Purity of Copper Scratches in Copper Surface Solder Float Test Solvent Resistance Surface Resistivity Volume Resistivity Terminology Thickness & Thickness Variation Warp or Twist Water Absorption Section 13 19 14 16 15 15 17 10 14 20 21 11 11 18 12 1.3 Metric units are the preferred units for these test methods Inch-pound units, where shown, are presented for information only 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use For specific hazard statements, see 7.2.1, 8.1, and 11.3.1 Terminology 3.1 Definitions: Definitions of terms used in these test methods are found in Terminology D1711 3.2 Definitions of Terms Specific to This Standard: For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org For Annual Book of ASTM Standards volume information, refer to the standard’s Document Summary page on the ASTM website The last approved version of this historical standard is referenced on www.astm.org Available from National Electronic Manufacturer’s Association (NEMA), 2101 L St., NW, Washington, DC 20037 These test methods are under the jurisdiction of ASTM Committee D09 on Electrical and Electronic Insulating Materials and are the direct responsibility of Subcommittee D09.07 on Flexible and Rigid Insulating Materials Current edition approved Nov 1, 2012 Published November 2012 Originally approved in 1990 Last previous edition approved in 2004 as D5109 – 99(2004) DOI: 10.1520/D5109-12 *A Summary of Changes section appears at the end of this standard Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959 United States D5109 − 12 3.2.1 blister, copper, n—a gas pocket (a void) located at the interface of the dielectric and the copper foil in a copper-clad laminate temperatures It is important that such exposure not adversely affect the suitability of the dielectric portion of the laminate for its intended use 3.2.2 blister, core, n—a gas pocket (a void) located between the laminations in the dielectric core of a copper-clad laminate 7.2 Procedure: 7.2.1 Take a specimen of laminate of 10 to 40–cm area Etch all of the copper from the specimen in accordance with Practice D1825 (Warning—it is possible that some of the solvents used in the printed wiring board industry are physiologically hazardous substances Such substances are to be used only where adequate ventilation is provided and in such a manner as to avoid absorption through the skin Take precautions to condense any vapors and return them to the boiling liquid.) 7.2.2 Using appropriate apparatus to generate and maintain the vapor phase, suspend the specimen in solvent vapors for approximately 3.2.3 dimensional instability—a characteristic of a solid material that is displayed by changes in the dimensions of a test specimen when the specimen is subjected to environments similar to those that the material may encounter during the manufacturing operations or use 3.2.4 peel strength, n—a force required to separate copper foil from the surface of a copper-clad laminate using a specific test method It is reported as a force per unit width 3.2.5 trace, n—in the printed wiring board industry, an electrically conducting element of a printed circuit board that remains on the laminate surface after etching NOTE 1—An appropriate apparatus consists of a vessel for heating liquid solvent and a reflux condenser in which the specimen can be placed so that it is in contact with the vapor phase of the boiling (condensing) solvent Conditioning 4.1 Unless otherwise stated in these test methods, condition test specimens in accordance with the provisions stated in Specification D1867 for the property of interest If that standard does not specify conditioning requirements, use the conditioning requirements of Practice D618 7.2.3 At the conclusion of this exposure, examine the surfaces of the specimen for any evidence of blistering or delamination 7.3 Report—Report the following information: 7.3.1 Any visible evidence of blistering or delamination It is possible that such behavior will be sufficient cause for judging that the laminate is not resistant to the solvent used 7.3.2 The identification of the laminate tested 7.3.3 The identification of the solvent used Purity of Copper 5.1 Significance and Use—Since the electrical conductance of copper can be adversely affected by small amounts of impurities, this test provides assurance that the circuits fabricated from the laminate will provide sufficient conductance for signal transmission The grain structure and the porosity of copper also affect conductance 7.4 Precision and Bias: 7.4.1 No statement is made about the precision or bias of this test method for measuring resistance to solvents since the result merely states whether there is conformance to the criteria for acceptability specified in the procedure 5.2 Procedure—Analyze the copper for purity in accordance with Test Methods E53 5.3 Report the following information: 5.3.1 The amount of copper, %, and 5.3.2 The identity of the laminate sampled for testing Solder Float Test 8.1 Significance and Use—Many printed wiring boards are populated with components followed by soldering either manually or with a wave soldering process A popular circuit design uses a fabrication process known as soldermask over bare copper (SMOBC) in which the laminate is submerged in molten solder In either of these two cases, the laminate is subjected to exposure to molten solder temperatures for short periods of time This test method provides useful information about the suitability of both clad and unclad laminate to survive these exposures (Warning—Molten solder can cause severe burns Exercise care to prevent injury.) 5.4 Precision and Bias: 5.4.1 See Test Methods E53 Warp or Twist 6.1 Significance and Use—Flat laminate material of large area per sheet is desirable for the most efficient fabrication of bare circuit boards Lack of warp or twist is very necessary for efficient placement of components on the fabricated but unpopulated circuit boards particularly if automatic insertion machinery is used to install components on the circuit boards 8.2 Unetched Laminate: 8.2.1 Prepare test specimens of unetched laminate having dimensions 25 by 25 mm by any thickness For laminate clad on both sides, two specimens are required, one for each side If specimens that survive the solder dip exposure are to be used for peel strength tests in accordance with Section 9, at least three specimens are required 8.2.2 Procedure—Float an unfluxed, unetched specimen, copper side down, on clean molten tin/lead 60/40 solder that is at the temperature specified in Specification D1867 for the 6.2 Procedure—Determine warp or twist on full size laminate sheets that are in the “as is” condition Test and report the results in accordance with Test Methods D229 Solvent Resistance 7.1 Significance and Use—Solvents are often used for processing or cleaning purposes in the fabrication of printed wiring boards The solvents are used sometimes at elevated D5109 − 12 and the copper foil There is no significance to this test in relation to the forces potentially exerted upon any trace on any circuit boards in service thickness of the laminate being tested At the end of the time specified in Specification D1867, remove the specimen and examine the copper surface for evidence of blisters For laminate clad on two sides, use a fresh specimen for testing each side 9.3 it is acceptable to use the specimens that passed the solder float test of 8.3.2 for the room temperature peel strength tests since they contain the etched patterns required for peel tests Otherwise, using the procedures of Practice D1825, etch patterns as in Fig on at least three specimens of copper-clad laminate 8.3 Etched Laminate: 8.3.1 A specimen is unconditioned laminate of any thickness which is 50 by 50 mm Etch each specimen in accordance with Practice D1825 so as to have an etched pattern as in Fig 8.3.2 Procedure: 8.3.2.1 Float the unfluxed specimen with its etched copper trace side to be tested down on clean molten 60/40 tin/lead solder at the temperatures and for the times shown in Specification D1867 8.3.2.2 At the end of the time specified for each grade, remove the specimen, allow it to cool to room temperature, and then examine it for evidence of: (1) blistering between layers of laminate, (2) blistering between copper and substrate, or (3) delamination of the copper foil 8.3.2.3 For double-sided clad laminate, use a fresh specimen for examining each side If no delamination or blistering is seen, it is acceptable to use the specimens that were exposed to solder dip for the peel strength tests of Section 8.3.3 Report—Report the following information: 8.3.3.1 Any evidence of blistering between laminate layers, 8.3.3.2 Any evidence of blistering between the copper and any substrate, and 8.3.3.3 Any delamination of the copper foil from the substrate 9.4 Procedure—Peel back the copper foil from the 6-mm end of the copper strip for approximately 25 mm so that the line of peel is perpendicular to the surface of the substrate Clamp each specimen, or hold it on a horizontal surface with the peeled copper strip up, providing a 25-mm span Grip the end of the peeled strip between two knurled jaws of a clamp Attach a flexible chain to a dial-indicating force indicator that has been adjusted to compensate for the weights of the chain and the clamp Adjust the jaws to cover the full width of the copper strip and clamp them parallel to the line of peel With the force indicator in a vertical plane, exert a steady vertical pull (approximately 50 mm/min) until the needle indicator shows a constant reading If the full width of the copper strip does not peel, discard this specimen and repeat the procedure on another specimen Make at least three tests and record the test result in accordance with Practice D3636 9.5 Report—Report the following information: 9.5.1 The identity of the laminate, 9.5.2 The room temperature peel strength test result after solder float in N/mm of width, and 9.5.3 The total number of strips tested Peel Strength Test 9.6 Precision and Bias: 9.6.1 This test has been in use for many years, but no information has been presented to ASTM upon which to base a statement of precision No activity has been planned to develop such information 9.6.2 This test method has no bias because the value for peel strength is determined solely in terms of this test method itself 9.1 This test is performed at room temperature on specimens of laminate that have previously been subjected to the solder float test 9.2 Significance and Use—This test method is useful for evaluating laminate for the detrimental effects, if any, due to soldering or other exposure to elevated temperature, upon the integrity of the bond interface between the dielectric substrate 10 Peel Strength Test at Elevated Temperature 10.1 There are two procedures, identified as Procedure A and Procedure B Only one is required No preference is given here for either procedure Procedure A uses the narrow (3.2–mm) peel strength strips etched using the pattern in Fig Procedure B uses an unconditioned copper-clad laminate for preparing specimens on which are etched 25 by 100–mm patterns for peel strength test strips Procedure B is often used for quality control purposes 10.2 Significance and Use: 10.2.1 Either procedure of this test method provides information that deals with the integrity of the adhesive bond between the copper foil and the dielectric while the laminate is at an elevated temperature It is possible that such temperatures will be encountered in fabricating circuit boards or in assembly operations, but the forces exerted in this test are not related in any way to the manner in which forces are likely to be encountered by the laminate in service or during fabrication or assembly FIG Test Specimen for Peel Strength and Solder Float Tests D5109 − 12 11.2 Specimens—Both surface and volume resistivity can be measured on a laminate clad on two sides by etching appropriate electrodes on both surfaces Single-sided laminate can be etched and the No electrode of Test Methods D257, Fig 4, can be applied to the unclad surface using porous silver paint 11.2.1 Use 100–mm by 100–mm pieces of laminate Etch, using Practice D1825 procedures, to produce concentric electrodes as in Fig of Test Methods D257 The dimensions of the pattern shall be: 10.2.2 It is possible that either procedure will show a drastic reduction in the peel strength at elevated temperature compared to the peel strength at room temperature if the test temperature exceeds the glass transition temperature of the polymer resin system used to make the laminate 10.3 Apparatus—The apparatus is described in NEMA Publication LI 1-1975 10.4 Specimens: 10.4.1 The number of specimens will be dictated by the grade of copper-clad laminate being tested Prepare at least two specimens for the lengthwise direction and two specimens for the crosswise direction See Test Methods D229 for explanations of these terms Laminate that is clad on two sides will require four additional specimens, two for each side Laminate clad on one side will require only four specimens 10.4.2 Prepare specimens for use with Procedure A in accordance with 8.2.1 10.4.3 Prepare specimens for use with Procedure B in accordance with 8.2.1, except use a sample of unconditioned copper-clad laminate and etch a pattern on it which comprises four peel strength strips each having dimensions of 25 by 100 mm D 50 mm (1) D 62.5 mm D 75 mm 11.2.2 If necessary, it is acceptable to apply electrodes having the preceding dimensions to a laminate from which all of the copper has been etched, by coating or spraying with a porous conductive silver paint (see Test Methods D257, Section 6, on Electrode Systems) 11.2.3 Condition all specimens for 96 h at 35°C in a chamber maintained at 90 % relative humidity (see Practice D618) The specimens are to be tested in equilibrium with this environment 10.5 Procedure: 10.5.1 Place the specimens in an oven in which the air is maintained at 150 2°C, At the end of a 60–min exposure, remove each specimen and test in accordance with 9.4 and NEMA Publication LI 1-1975 The NEMA document calls for the testing to be performed at 150°C 10.5.2 Record the test results of peel strength as N/mm width in accordance with Practice D3636 Alternatively, record the test results as lbf/in of width in accordance with Practice D3636 11.3 Procedure: 11.3.1 Warning—Lethal voltages are a potential hazard during the performance of this test It is essential that the test apparatus, and all associated equipment electrically connected to it, be properly designed and installed for safe operation Solidly ground all electrically conductive parts which it is possible for a person to contact during the test Provide means for use at the completion of any test to ground any parts which were at high voltage during the test or have the potential for acquiring an induced charge during the test or retaining a charge even after disconnection of the voltage source Thoroughly instruct all operators as to the correct procedures for performing tests safely When making high voltage tests, particularly in compressed gas or in oil, it is possible for the energy released at breakdown to be suffıcient to result in fire, explosion, or rupture of the test chamber Design test equipment, test chambers, and test specimens so as to minimize the possibility of such occurrences and to eliminate the possibility of personal injury If the potential for fire exists, have fire suppression equipment available 11.3.2 Test the specimens in the chamber which is at 35°C and 90 % relative humidity in accordance with the principles in Test Methods D257 Apply a direct voltage of 500 V for 60 s between electrodes and of Fig in Test Methods D257 11.3.3 Measure the resistance between electrodes and of Fig in Test Methods D257 Compute the volume resistivity for the electrode dimensions of 11.2 using the equation in Table of Test Methods D257 and the thickness of the etched laminate obtained in accordance with Section 17 11.3.4 Move the leads so that the voltage is applied between electrodes and of Fig in Test Methods D257 Apply the voltage for 60 s Measure the resistance between electrodes and Use the equation in Table of Test Methods D257 to compute the surface resistivity of each specimen 10.6 Report—Report the following information: 10.6.1 Identity of the laminate, 10.6.2 Which of the two procedures was used, 10.6.3 The test results and units for each direction tested, 10.6.4 The test results and units for each copper side tested, and 10.6.5 The number of strips that failed to peel across the entire width of strip 10.7 Precision and Bias: 10.7.1 This test has been in use for many years, but no information has been presented to ASTM upon which to base a statement of precision No activity has been planned to develop such information 10.7.2 This test method has no bias because the value for peel strength is determined solely in terms of this test method itself 11 Volume Resistivity and Surface Resistivity 11.1 Significance and Use—In printed wiring boards it is desirable to maintain high electrical resistance between traces on the surface of the board Volume resistivity is one element that can affect the impedance of a circuit and often the impedance is critical See also Test Methods D257 for more detailed information regarding significance of these properties D5109 − 12 13.1.3 This test method is suitable as a quality control test for estimating continuity of quality 11.4 Report—Report the following information: 11.4.1 The identity of the laminate, 11.4.2 The volume resistivity, MΩ-cm, 11.4.3 The surface resistivity, Megohms per square, and 11.4.4 Whether silver paint was applied, and if so, where 13.2 Specimens: 13.2.1 From laminate pieces 50 by 75 mm, remove all of the copper by etching in accordance with Practice D1825 13.2.2 Condition the specimens in accordance with Practice D618, Procedure E, which is immersion in distilled water for 48 h at 50°C followed by cooling submersed in distilled water for sufficient time to attain 23°C 11.5 Precision and Bias: 11.5.1 This test has been in use for many years, but no information has been presented to ASTM upon which to base a statement of precision No activity has been planned to develop such information 11.5.2 This test method has no bias because the value for resistivity is determined solely in terms of this test method itself 13.3 Procedure—Determine the dielectric breakdown voltage parallel to laminations on the moisture-conditioned specimens using the step by step test in accordance with the tapered pin method of Test Methods D229 Record the test result in accordance with Practice D3636 12 Water Absorption 13.4 Report—Report the following information: 13.4.1 The identity of the laminate tested, 13.4.2 The test result of the dielectric breakdown voltage, and 13.4.3 The nature of the surrounding medium used 12.1 Significance and Use—This test method provides information about the amount of water absorbed in the laminate Absorbed water can be detrimental to mechanical and to electrical insulating characteristics of the circuits produced from the laminate Absorbed water in laminate can create problems during fabrication of circuit boards The test is also useful in estimating the uniformity of quality of the laminate 13.5 Precision and Bias: 13.5.1 This test has been in use for many years, but no information has been presented to ASTM upon which to base a statement of precision No activity has been planned to develop such information 13.5.2 This test method has no bias because the value for dielectric breakdown voltage is determined solely in terms of this test method itself 12.2 Test Specimens—Etch the copper from four pieces of laminate 75 by 25 mm in accordance with Practice D1825 12.3 Procedure—Determine the water absorption in accordance with Test Methods D229 using immersion time of 24 h at a temperature between 21 and 25°C 12.4 Report the following information: 12.4.1 The average water absorption for all specimens tested, and 12.4.2 The identification of the laminate tested 14 Permittivity and Dissipation Factor 14.1 Significance and Use—Circuit boards in some applications require the use of controlled impedance circuitry Knowledge of the permittivity of the dielectric between the copper cladding is required for the design of such circuits In circuits the dielectric losses of the dielectric between the copper cladding is one of the contributors to power loss in the circuit Dielectric losses are affected by dissipation factor of the laminate 12.5 Precision and Bias: 12.5.1 This test has been in use for many years, but no information has been presented to ASTM upon which to base a statement of precision No activity has been planned to develop such information 12.5.2 This test method has no bias because the value for water absorption is determined solely in terms of this test method itself 14.2 Specimens—In some test apparatus arrangements, the capacitance of the test specimen influences the sensitivity of the null point determination with a resulting influence upon the precision of measurements of dissipation factor and permittivity This fact often dictates the dimensions of specimens (See Test Methods D150, and the instruction manuals provided by the manufacturer of the electrical test apparatus being used for a more comprehensive discussion of these effects.) If the two-fluid methods of Test Method D1531 are used, the size of the specimens will be dictated by the test cell geometry 14.2.1 Select the size of the test specimens in accordance with thickness of the dielectric core of the laminate as shown in Table 13 Dielectric Breakdown Voltage Parallel to Laminations on Moisture-Conditioned Specimens 13.1 Significance and Use: 13.1.1 Industrial laminates used for the dielectric in copperclad laminate were, and are still, used for electrical applications in which voltage stresses are exerted between conductors that are placed in holes in the unclad laminate Use of unclad laminate in this configuration led to the development of this test method There is debate as to the significance of this method 13.1.2 Circuit boards are frequently used in service in applications such that the full thickness of the core insulation between the copper cladding is exposed to voltage stress parallel to the flat sides of the laminate between pin-type inserts With the use of moisture-conditioned specimens this test method simulates the conditions likely to be found in service TABLE Specimen Size for Permittivity TestA Thickness 1.2 mm and under over 1.2 mm to 2.4 mm over 2.4 mm to 6.5 mm A Metric conversion 0.001 in = 0.0254 mm Specimen Size 50 by 50 mm 75 by 75 mm 100 by 100 mm D5109 − 12 15.4.5 Any other flexural properties obtained from the test 14.2.2 If Test Methods D229 are to be used, print and etch an electrode pattern using the etch procedures of Practice D1825 if single or double sided copper-clad laminate is to be tested Single sided laminate will require the application of porous conducting silver paint for the electrode on the unclad side of the laminate 14.2.3 If Test Method D1531 methods are to be used, etch all copper from and clean the specimen in accordance with Practice D1825 so as to obtain a clean dielectric sheet for testing 14.2.4 Condition all etched specimens in accordance with Practice D618, Procedure A, prior to testing 15.5 Precision and Bias: 15.5.1 This test has been in use for many years, but no information has been presented to ASTM upon which to base a statement of precision No activity has been planned to develop such information 15.5.2 This test method has no bias because the value for flexural strength is determined solely in terms of this test method itself 16 Flammability Rating NOTE 2—Flammability rating was formerly called “rate of burning.” This has been deprecated in preference to the expression “FR” which is defined in Terminology D1711 14.3 Procedure—Determine the permittivity and the dissipation factor on the conditioned specimens in accordance with either Test Methods D1531 or Test Methods D229 Unless otherwise specified, make all tests at MHz and room temperature 16.1 Significance and Use—Many circuit boards are used in applications for which regulatory agencies demand decreased risks from fire hazards It has been established that flammability rated laminates are preferred for use in such applications 14.4 Report—Report the following information: 14.4.1 The identity of the laminate tested, 14.4.2 The test results for permittivity, 14.4.3 The test results for dissipation factor, 14.4.4 The method used (Test Methods D1531 or Test Methods D229), 14.4.5 The temperature and the frequency used, and 14.4.6 Any deviation from the requirements of these test methods which were used to make the measurements 16.2 Specimens—From a sufficient area of copper-clad laminate, etch away the copper in accordance with Practice D1825 Cut the area into 20 pieces, each 13 by 127 mm 16.3 Procedure—Perform the tests in accordance with Method I of Test Methods D229 16.4 Report—Report the following information: 16.4.1 The identity of the laminate tested, 16.4.2 The thickness of the laminate after etching, and 16.4.3 The classification (as in Table of Test Methods D229) for the laminate with respect to its flammability rating 14.5 Precision and Bias: 14.5.1 This test has been in use for many years, but no information has been presented to ASTM upon which to base a statement of precision No activity has been planned to develop such information 14.5.2 This test method has no bias because the value for permittivity and dissipation factor is determined solely in terms of this test method itself 16.5 Precision and Bias: 16.5.1 This test has been in use for many years, but no information has been presented to ASTM upon which to base a statement of precision No activity has been planned to develop such information 16.5.2 This test method has no bias because the value for flammability rating is determined solely in terms of this test method itself 15 Flexural Strength (flatwise) 15.1 Significance and Use—See Test Methods D229 15.2 Some specifications or other purchase documents specify that flexural strength of copper-clad laminate be measured at room temperature or at some specific elevated temperature Unless otherwise stated, all flexural properties, including strength, are to be measured at room temperature on specimens of copper-clad laminate from which all of the copper has been etched 15.2.1 Grades G-11 and FR-5 are copper-clad laminates that are described as “temperature resistant types.” Such laminates require testing for flexural strength at elevated temperatures of 150°C 17 Oven Blister Test 15.3 Measure flexural properties in accordance with Test Methods D229 17.2 Specimens—Cut four pieces of copper-clad laminate into 150 by 150 10–mm specimens Etch two of these pieces in accordance with Practice D1825 and leave the other two unetched 17.1 Significance and Use: 17.1.1 The processing of laminates into circuit boards often requires the exposure of laminate for short time periods (several minutes) to elevated temperatures as high as 180°C This test provides some information regarding the suitability of the laminate for use at such process conditions 17.1.2 The results of this test method are not to be used in any way to judge or infer the continuous use temperature of any copper-clad laminate 15.4 Report—Report the following information: 15.4.1 The identity of the copper-clad laminate tested, 15.4.2 The temperature of testing, 15.4.3 The time of exposure of specimens to elevated temperatures prior to testing, 15.4.4 The flexural strength test result, and 17.3 Procedure: 17.3.1 Place the four specimens into a horizontal-flow air-circulating oven maintained at the temperature required by Table of Specification D1867 D5109 − 12 18.5.2 Calculate the absolute difference between the nominal thickness of the laminate and each of the individual test measurements recorded in 18.4.2 18.5.3 Record the individual difference from the nominal thickness for each of the test measurements 18.5.4 Compare each difference to the maximum thickness tolerance allowed by the material specification (see Specification D1867 or the purchase documents) 18.5.5 Record the greatest individual difference of 18.5.3 as the thickness variation for the laminate 17.3.2 Support the specimens vertically in the oven on nonmetallic racks so that the plane of the specimen is parallel to the air flow 17.3.3 At the end of the time specified in Table of Specification D1867 remove the specimens and allow them to cool to room temperature 17.3.4 Examine each specimen and note any sign of blistering NOTE 3—A blister formed between the copper foil and the dielectric substrate is called a “copper blister.” If a blister forms within the dielectric substrate, it is called a “core blister.” See 3.2.2 18.6 Report—Report the following information: 18.6.1 The complete identification of the laminate, 18.6.2 The date of testing, 18.6.3 The test result for the thickness of each specimen, 18.6.4 The thickness variation for each specimen, and 18.6.5 A statement describing any deviations from the requirements of these test methods used in the performance of the tests 17.4 Report—Report the following information: 17.4.1 The identity of the laminate, 17.4.2 The temperature of the oven, 17.4.3 The time of exposure to elevated temperature, and 17.4.4 A statement about the presence of blisters or lack thereof 17.5 Precision and Bias: 17.5.1 No statement is made about either the precision or bias of this test method for determining blisters in copper-clad laminates since the result merely states whether there is conformance to the criteria for success specified in the procedure 18.7 Precision and Bias: 18.7.1 The precision of this test method has not been determined It is to be expected that with competent, trained operators in a reasonably well equipped laboratory using calibrated apparatus, the replication of thickness and thickness variation between two operators testing the same specimens from the same lot of copper-clad laminate will be within 65 % of the mean value for thickness and within 610 % for the thickness variation of the laminate 18.7.2 This test method has no bias because the value for thickness is determined solely in terms of this test method itself 18 Thickness Dimensions and Thickness Variation 18.1 Significance and Use: 18.1.1 Precise imaging of printed circuits on copper-clad laminates can be affected by the actual laminate thickness and the variability of same 18.1.2 Variation in thickness of copper-clad laminates is undesirable if the circuit boards are to be populated with components using automatic “pick-and-place” machinery 19 Dimensional Instability 19.1 Significance and Use: 19.1.1 Precise registration of artwork and tooling holes is necessary during the processing of printed wiring boards This requires a laminate which exhibits either minimal or predictable changes in dimensions during excursions to elevated temperatures or humidities, and exposure to aqueous liquids that are encountered during the fabrication of circuits 19.1.2 Any copper-clad laminate will change dimensions if subjected to extreme conditions of temperature, pressure, or humidity It is proper therefore, to refer to instability of dimensions rather than dimensional stability 18.2 Apparatus—See Test Methods D374 for apparatus description 18.3 Specimen—A specimen shall be a single sheet of laminate having dimensions 300 by 300 30 mm The specimen shall be either copper-clad or it shall be a sheet from which all of the copper has been etched in accordance with Practice D1825 18.4 Procedure for Thickness: 18.4.1 Take specimens that are in equilibrium with standard laboratory conditions (see Practice D618) and make at least one test measurement on each of at least ten different areas of each specimen using the apparatus described for Method A in the Apparatus section of Test Methods D374, (see Practice D3636 for meaning of “test measurement”) 18.4.2 Record the value of each test measurement 18.4.3 Compute the arithmetic mean of all of the test measurements Record this mean value as the test result for the thickness of the specimen 19.2 Apparatus: 19.2.1 An instrument, usually a mechanical, electronic, or an optical device graduated so as to differentiate between dimensions of 2.5 and 5.0 µm (0.0001 and 0.0002 in.) throughout a span of at least 0.6 m 19.2.2 An oven capable of maintaining temperature control at 150 2°C 19.2.3 Etching facilities to etch laminate in accordance with Practice D1825 18.5 Procedure for Thickness Variation: 18.5.1 Refer to the purchase order, or a material specification, for a nominal thickness value for the laminate being examined In the case of Specification D1867, nominal thickness values are shown in Table in the column headed “Nominal Overall Laminate Thickness.” 19.3 Specimens: 19.3.1 Take a full size laminate sheet in the “as-received” condition Mark this sheet with arrows and labels denoting lengthwise (LW) and crosswise (CW) directions See Test Methods D229 for descriptions of these terms D5109 − 12 19.4.6 Repeat the measurements of 19.4.1 and 19.4.2 and record each dimension either as “after bake LW” or “after bake CW.” 19.3.2 Cut from this sheet three specimens that are approximately 0.3 by 0.3 m each 19.3.3 Mark each specimen with arrows denoting LW and CW 19.3.4 Place the specimens in a standard laboratory atmosphere as described in Practice D618, Procedure A 19.3.5 After conditioning, apply eight target marks on each specimen such that the target marks are placed in accordance with Fig All target marks shall be resistant to etching processes 19.5 Calculation: 19.5.1 Each specimen has three sets of distance measurements for the lengthwise dimensional instability determination Calculate the percent change in each of the lengthwise dimensions due to etching by taking 100 times the ratio of “after etch LW” minus “O—LW” divided by “O—LW.” A negative value is shrinkage; a positive value is growth 19.4 Procedure: 19.4.1 Using specimens that are in equilibrium with the standard atmosphere described in 19.3.4, measure the distance to the nearest µm between the two target marks identified in Fig as and Record this distance as “O—LW.” Repeat for the other two pairs of target marks in the lengthwise direction 19.4.2 Using specimens that are in equilibrium with the standard atmosphere described in 19.3.4, measure the distance to the nearest µm between the two target marks identified in Fig as and Record this distance as “O—CW.” Repeat for the other two pairs of target marks in the crosswise direction 19.4.3 Etch all copper from each specimen in accordance with Practice D1825 19.4.4 Clean each specimen in accordance with Practice D1825 After cleaning, dry each specimen at 40°C for 16 h After conditioning in accordance with 19.3.4, repeat the distance measurements of 19.4.1 and 19.4.2 Record the dimension for each direction either as “after etch LW” or “after etch CW.” 19.4.5 Place each specimen into an oven which is controlled at 150 2°C Allow the specimens to bake for 30 Remove specimens from the oven and allow them to come to equilibrium with the standard laboratory atmosphere of Practice D618, Procedure A 100 @ ~ after etch LW! ~ O LW! # ÷ @ ~ O LW! # (2) 19.5.2 Compute the arithmetic average from the three sets of “after etch” measurements This average is the test measurement for dimensional instability due to etch on one specimen Repeat the calculation for each specimen The average of the three test measurements is the test result for dimensional change due to etch for the lengthwise direction 19.5.3 For the crosswise direction dimensional instability after etch, repeat the calculations of 19.5.1 and 19.5.2 using appropriate crosswise direction dimensions 19.5.4 For the after etch and bake dimensional instability values repeat the calculations of 19.5.1 and 19.5.2 using the dimensional data obtained after etch and bake on each specimen and in each of the two directions 19.6 Report—Report the following information: 19.6.1 Complete identification of the laminate, 19.6.2 The lengthwise dimensional instability after etch, %, 19.6.3 The lengthwise dimensional instability after etch and bake, %, 19.6.4 The crosswise dimensional instability after etch, %, 19.6.5 The crosswise dimensional instability after etch and bake, %, and 19.6.6 Any deviations from the procedures set forth in these test methods 19.7 Precision and Bias: 19.7.1 This test has been in use for many years, but no information has been presented to ASTM upon which to base a statement of precision No activity has been planned to develop such information 19.7.2 This test method has no bias because the value for dimensional instability is determined solely in terms of this test method itself 20 Keywords 20.1 copper-clad laminate; dielectric breakdown parallel to laminations; dimensional instability; dissipation factor; fiber reinforced; flexural strength; industrial laminate; laminate; oven blister; peel strength; permittivity; printed circuit boards; printed wiring boards; rigid laminate; solder float; surface resistivity; thermoset; thickness variation; trace; twist; volume resistivity; warp; water absorption FIG Target Marks D5109 − 12 SUMMARY OF CHANGES Committee D09 has identified the location of selected changes to this specification since the last issue, D5109 – 99R04, that may impact the use of this specification (Approved November 1, 2012.) 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